A federal judge has upheld Arizona's ban on abortions at 20 weeks of pregnancy.

U.S. District Judge James Teilborg said the new law may prompt women to make decisions about abortions earlier, but it is constitutional because it does not prohibit them from making that decision.

"In choosing to put a limit on abortions past 20 weeks gestational age, the Arizona Legislature cited to the substantial and well-documented evidence that an unborn child has the capacity to feel pain during an abortion by at least 20 weeks gestational age," he wrote in his 15-page decision.

This new law bans abortions about four weeks earlier than previous restrictions.

Arizona is now one of 10 states to enact a 20-week ban. The law takes effect Thursday.

The Center for Reproductive Rights is appealing the decision to the 9th U.S. Circuit Court of Appeals.